Known is a sandwich panel including the outer skins connected with the core layer while said core is obtained by means of sheet blank bending along the marked-out on the development zigzag lines of protrusions and recesses (Inventors' certificate SU no. 1,785,154. Method for production of curvilinear sandwich panel with zigzag corrugated core.—Int. Cl.: B 23 K 20/00.—Bulletin no. 28 of 30 Jul. 1993).
The main short-comings of herein-presented panel are low strength and reliability of skin-core bonding due to small contact area.
Known is a sandwich panel with light core from corrugated sheet material (RF Patent no. 2,038,265 C1. Sandwich panel.—Int. Cl.: B 64 C 3/26.—Published on 27 Jun. 1995). With the aim to enlarge the contact area of the core with the lower skin, the crimp ridges are made in the form of lenticular elements placed at the recesses of side ridges, whereas located between the side ridges of the core at its vertices curvilinear composite material enlarges the contact area of the core with the upper skin.
The main short-comings of herein-presented panel are the loss of simplicity of the core shaping along the recesses lines of the crimps and high labor expenditures for performing the contact areas along the protrusions lines; it results in writing up of the panel in whole.
Taken as a prototype is a sandwich panel including the skins and placed between said skins zigzag corrugated core with alternating protrusions and recesses containing going along said protrusions and recesses triangular grooves filled with adhesive composite material (Inventors' certificate RF no. 1,646,196 A1. Sandwich panel.—Int. Cl.: B 64 C 3/26.—Bulletin no. 36 of 27 Dec. 1996).
The main short-coming of herein-presented panel is the complexity of the crimp shape in its lateral section which requires some sophisticated and expensive shaping tooling for production of core. Moreover, technological hardships make it impossible to produce the grooves on the protrusions and recesses of the crimp at its relatively small height. The extra fold in the crimp shape brings down the core block height accuracy; it adversely affects the quality of the panel. Technically realizable dimensions of the grooves section increase the area and, therefore, the mass of the core which requires the increased application of adhesive composite material which also adversely affects the weight efficiency of the panel.